A framework to analyze the propagation of measurement noise through backprojection reconstruction algorithms in electrical impedance tomography (EIT) is presented. Two
measurement noise sources were considered: noise in the current drivers and in the voltage detectors. The influence of the acquisition system architecture (serial/semi-parallel) is also discussed. Three variants of backprojection reconstruction are studied:
basic (unweighted), weighted and exponential backprojection.
The results of error propagation theory have been compared with those obtained from simulated and experimental data. This
comparison shows that the approach provides a good estimate of the reconstruction error variance. It is argued that the reconstruction error in EIT images obtained via backprojection can be approximately modeled as a spatially nonstationary Gaussian
distribution. This methodology allows us to develop a spatial characterization of the reconstruction error in EIT images.